Alternatives · 15 models compared · checked 17 Aug 2026
GPT-5.6 Terra alternatives: 15 models in or near grid E6
The closest model to GPT-5.6 Terra on the atlas is Grok 4.20, in the same square, at $1.25 per 1M input tokens against GPT-5.6 Terra’s . 8 of the 15 nearest models are cheaper on input; the cheapest is Grok 4.20 at $1.25. We rank by position on the atlas, not by capability, because we hold no capability data.
$2.00
observed We measured
- Source
- Our catalogue
- Retrieved
- 17 Aug 2026
Ask an AI about this pageGChatGPTCClaudePPerplexityGeGeminiXGrok
Cite
Cite this page
ModelsAtlas. “GPT-5.6 Terra alternatives: 15 models in or near grid E6”. Retrieved 17 Aug 2026. https://modelsatlas.com/models/openai/gpt-5-6-terra/alternatives
Where the alternatives sit
Each square is a price band (A–H) × a context band (1–6). How the grid works
Same squareGRIDE66 modelsGPT-5.4, GPT-5.6 Sol, GPT-6 Sol and 3 more
GPT-5.6 TerraIts 15 nearest modelsOther modelsOpen weights
View the map as a table (2 squares)
| Square | Price band | Context band | Models |
|---|---|---|---|
| GRIDE5 | $1–3 | 1M | Gemini 2.5 Pro Preview 06-05, Grok 4.3, Muse Spark 1.1, Muse Spark 1.2, Muse Spark 1.3, Gemini 3.5 Flash, Claude Sonnet 5, Claude Sonnet 5.5, Gemini 3.1 Pro Preview |
| GRIDE6 | $1–3 | >1M | GPT-5.6 Terra, Grok 4.20, Grok 4.20 Multi-Agent, GPT-5.6 Sol, GPT-6 Sol, GPT-6.1 Sol, GPT-5.4 |
Top 15 alternatives
Ranked by steps away on the atlas, then cheaper before pricier, then input price
| # | Model | Grid | Why it fits | Input / 1M | vs GPT-5.6 Terra | Output / 1M | Context | |
|---|---|---|---|---|---|---|---|---|
| — | GPT-5.6 TerraOpenAI · the model you’re replacing | GRIDE6 | Baseline | $2.00 | — | $12.00 | 1.05M | |
| 1 | Grok 4.20xAI | GRIDE6 | Same square, 38% cheaper input, 1.9× the context | $1.25 | −37% | $2.50 | 2M | Compare → |
| 2 | Grok 4.20 Multi-AgentxAI | GRIDE6 | Same square, 38% cheaper input, 1.9× the context | $1.25 | −37% | $2.50 | 2M | Compare → |
| 3 | GPT-5.6 SolOpenAI | GRIDE6 | Same maker, same square, same input price | $2.00 | same | $10.00 | 1.05M | Compare → |
| 4 | GPT-6 SolOpenAI | GRIDE6 | Same maker, same square, same input price | $2.00 | same | $10.00 | 1.05M | Compare → |
| 5 | GPT-6.1 SolOpenAI | GRIDE6 | Same maker, same square, same input price | $2.00 | same | $10.00 | 1.05M | Compare → |
| 6 | GPT-5.4OpenAI | GRIDE6 | Same maker, same square, 25% pricier input | $2.50 | +25% | $15.00 | 1.05M | Compare → |
| 7 | Gemini 2.5 Pro Preview 06-05Google | GRIDE5 | Neighbouring square E5, 38% cheaper input | $1.25 | −37% | $10.00 | 1.05M | |
| 8 | Grok 4.3xAI | GRIDE5 | Neighbouring square E5, 38% cheaper input | $1.25 | −37% | $2.50 | 1M | |
| 9 | Muse Spark 1.1Meta | GRIDE5 | Neighbouring square E5, 38% cheaper input | $1.25 | −37% | $4.25 | 1.05M | |
| 10 | Muse Spark 1.2Meta | GRIDE5 | Neighbouring square E5, 38% cheaper input | $1.25 | −37% | $4.25 | 1.05M | |
| 11 | Muse Spark 1.3Meta | GRIDE5 | Neighbouring square E5, 38% cheaper input | $1.25 | −37% | $4.25 | 1.05M | |
| 12 | Gemini 3.5 FlashGoogle | GRIDE5 | Neighbouring square E5, 25% cheaper input | $1.50 | −25% | $9.00 | 1.05M | |
| 13 | Claude Sonnet 5Anthropic | GRIDE5 | Neighbouring square E5, same input price | $2.00 | same | $10.00 | 1M | |
| 14 | Claude Sonnet 5.5Anthropic | GRIDE5 | Neighbouring square E5, same input price | $2.00 | same | $10.00 | 1M | |
| 15 | Gemini 3.1 Pro PreviewGoogle | GRIDE5 | Neighbouring square E5, same input price | $2.00 | same | $12.00 | 1.05M |
What switching saves
3,000 input + 800 output tokens × 1,000 requests a day
Σ Derived from standard-tier prices; excludes caching and batch discounts. Use your own numbers →
Larger-context alternatives
| Model | Input / 1M | Context | |
|---|---|---|---|
| Grok 4.20xAI | $1.25 | 2M | Compare |
| Grok 4.20 Multi-AgentxAI | $1.25 | 2M | Compare |
| Llama 4 ScoutMeta | $0.10 | 1.31M |
Free alternatives
| Model | Input / 1M | Context | |
|---|---|---|---|
| Lyria 3 Clip PreviewGoogle | Free | 1.05M | |
| Lyria 3 Pro PreviewGoogle | Free | 1.05M |
Compare GPT-5.6 Terra head to head
Questions
What is the best alternative to GPT-5.6 Terra?
Grok 4.20 ranks first: same square, 38% cheaper input, 1.9× the context. Input is $1.25 per 1M tokens against $2.00 for GPT-5.6 Terra. Ranking is by position on the atlas, not by quality.
What is the cheapest alternative to GPT-5.6 Terra?
Grok 4.20 at $1.25 per 1M input tokens, 38% less than GPT-5.6 Terra, among the 15 closest.
Is there an open-weight alternative to GPT-5.6 Terra?
None of the 15 closest is marked open-weight in our records.
Which alternative has a larger context window?
Grok 4.20 and Grok 4.20 Multi-Agent hold more than GPT-5.6 Terra's 1.05M; the largest is Grok 4.20 at 2M.
How are alternatives ranked?
By distance on the atlas grid from GPT-5.6 Terra's square E6: the same square first, then neighbouring squares. Within the same distance, cheaper models come before pricier ones, then the lowest input price wins. We hold no capability data, so we do not claim a model can do what GPT-5.6 Terra does, only that it costs and holds about the same. No vendor pays for position.
More alternatives
Keep going in your AI
Opens with this page as the source. We add nothing else to the prompt.
- What is the best alternative to GPT-5.6 Terra?
- What is the cheapest alternative to GPT-5.6 Terra?
- Is there an open-weight alternative to GPT-5.6 Terra?